cell communication Flashcards
how many cells are multicellular organisms made out of?
trillions of cells
how do cells coordinate activitues?
they “talk” to each other/ communicate
what kingdom in yeast from?
fungi
is yeast motile?
it is nonmotile
yeast is used to make what?
beer, bread, wine
name of yeast cell we study
Saccharomyces cerevisiae
what are the two sexes of mating types for yeast cell called?
a and alpha cell
how do two haploid yeast cells mate?
the a cell secretes a signaling molecule/pheromone (a factor) which binds to receptors on a nearby alpha cell
at the same time, the alpha cell secretes the alpha factor which binds to a receptor on the a cell
what does the attachment of a cell’s factor to another cell’s receptor do?
causes the cells to start shmooing
what is shmooing?
cells to elongate and grow toward each other
what happens when the two haploid cells meet each other?
they form a new diploid a/alpha cell
what is the more typical way for yeast cells to repoduce?
asexually by pinching off a parent cell - budding
bacteria can live as free-living cells called?
planktonic bacteria
how do bacteria cells communicate?
with small molecules that can be detected by other bacterial cells of the same species
what happens when the signaling molecules of bacteria cells gets high?
induces quorum sensing
what is quorum sensing?
bacteria are indicated that their densities are high enough to coordinate behaviors that can only be done by a given number of bacterial cells working together in synchrony
who discovered quorum sensing?
Bonnie Bassler
example of quorum sensing
formation of biofilm
what is biofilm ?
aggregation of bacterial cells adhered to a surface
slimy feeling on teeth each morning or on leaves in a forest path
what do cells get from the surfaces they are attached to?
typically derive nutrients
where was quorum sensing fist seen by Bassler?
in a species of bioluminescent bacteria called Vibrio fischeri that are mutualistic symbionts in the light producing organs of squid
how does Vibrio fischeri work?
as free-living planktonic cells, their signaling molecules are too low to produce light. however, in high concentrations, this triggers protein synthesis of luciferase that produces the characteristic glow
what does pathogenic mean?
disease causing
example of pathogenic bacteria using quorum sensing
rely on this to know when their densities are high enough to turn on their genes for virulence